This invention relates to a monitoring system for electric furnaces, and more particularly to an electronic system for monitoring individual heater elements so as to detect and identify individual element failures.
It has been known in the art to provide a variety of systems or devices to monitor the condition of electric furnace heater elements. Generally, however, such devices or systems have been expensive or cumbersome and inefficient. For example, one system has utilized electromechanical relays in determining the condition of heater elements, a center tap being required with such an arrangement. Moreover, this arrangement will not work for phase-fired systems. In addition, there has not been appropriate isolation between components of prior art systems.